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Heat Shield Follow Up

To: <spitfires@autox.team.net>
Subject: Heat Shield Follow Up
From: "Mike Perry" <mikep@michindust.com>
Date: Sun, 9 Apr 2000 14:04:34 -0400
Previous Problem:
>>After installing my dual HS4 setup, syncing the carbs (UNISYN) and
checking
the mixture (COLORTUNE), the car runs great, except when in stop and go
traffic or after an extended idle.  It "feels" like it is flooding itself,
and if I can stand the rough running and occasional backfire, it clears up
in about 1/4 to 1/2 mile.  It will remain running nicely until I get back
into the stop and go traffic.  In fact, it has never run better outside of
this problem...no stalls, and no hesitation all the way through the rev
band.

I installed Gross Jets in place of the float needles, but that does not
appear to have made a difference.

Other potentially useful information:
72 Spit
1296, low miles (6500 mi on rebuild)
Headers
Dual HS4s, recently rebuilt (within 800 miles
Monza Exaust
Low restriction air filters (foam element type)<<

Results:

Thanks to advice from the list, I have fabricated and installed a heat
shield, as well as 3/8" spacers between the carbs and the manifold.  (N)Ever
the scientist, I did both modifications at once so I would never know which
had the desired effect!

Long and short of it is that I do not seem to be overheating the carbs
anymore, and have gotten rid of the 1/4-1/2 mile hesitation and rough
running.  I can't say for certian, as it was only in the mid 40s today
(Michigan), but I duplicated all the troublesome schenarios without any
signs of trouble.

I do, however, occasionally have a momentary hesitation right at
accellertion (in no way similar to the original problem.  It doesn't last
any more than 1-2 seconds.  My guess in my float position(s) are out of
position causing a bit of flooding.  I believe one of the floats is badly
worn at the pin, which may restrict its movement.  Does this sound
reasonable?  Just looking for advice before I order parts.

Also, I now that I have my heat shield in place, I am beginning to install
my Lumitron EI kit.  Any suggestions as to where I want the timing set?  I
have the "book" info, but since my fuel system is so different from stock
now, I'm not completely confident.

Thanks for any help you might be able to provide!


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